Before we delve into details, it's important to discuss a couple of technical terms. SMD LED stands for 'surface mount LED'. The manufacturing process involves mounting the chip onto a small desk-like surface which eventually becomes an LED. The packaging process consists of three steps:
1. Mounting the chip onto a desk with the use of adhesives 2. Connecting the chip to the core system with a bond wire 3. Coloring the chip with a phosphor-based color.
For better understanding on how the naming system works, there is a simple rule to be followed. It's rather straightforward: each packaging process is named after its respective LED product dimensions. For example, '3528' means the product dimensions are 3.5*2.8mm.
The packaging processes of 2835, 3014 and 3528 are all based on Epistar and chips of similar dimensions. Generally speaking, SMD 2835's design is newer and more advanced than that of 3014 and 3528.
2835's thermal dissipation system is substantially more efficient, because it has a larger heat sink on the back than the 3014 does and 3528 has no back heat sink at all. This enables 2835 LED to take higher amounts of current and generate more luminous flux.
1. The larger the chip, the better if we take the 3528 as an example, its manufacturer could use a chip of either 10*16, 10*18 or 10*23 in dimensions in order to produce the LED. Although all of the three can be driven by 20ma, they each generate different luminous flux.
However, most of the lamp buyers will have a very hard time knowing the chip's actual brand and dimensions, and the only real way for them to find out is to subject the lamp to an optical performance test.
2. A controversial designHigher drive currents will produce more luminous flux and heat inside a chip.3528, 3014 and 2835 all use the 10*23mm chip, but the drive currents are different. It is controversial in the sense that although 3014 and 2835 have a larger heat sink, one chip in these packagings could be driven by higher currents. Still, it has become the most popular design by far.